This interesting open access paper reports on one of a number of efforts to map the details of the association between cardiovascular fitness and memory function over the course of aging. The brain is that the mercy of the vascular system in many ways. There is the age-related reduction in capillary formation cutting down the supply of nutrients and oxygen to the brain. Stiffening of blood vessels results in hypertension, and raised blood pressure pummels delicate tissue structures in the brain, kidney, and elsewhere. The structural decline of the vascular system, the weakening of blood vessels due to atherosclerotic lesions, combines with raised blood pressure to produce many ruptures of lesser blood vessels in the brain over the years, destroying small areas of functional tissue in silent, tiny strokes.
All of these processes are to some degree slowed by maintaining cardiovascular fitness – even capillary formation. Physical activity also adjusts many signaling processes related to tissue maintenance, such as the pace of neurogenesis in the brain, the production and integration of new neurons. To look at it the other way, in our modern age of comfort and indolence, most